Lockstitch sewing machine



Jan. 5, 1937.

L. E. TOPHAM LOCKSTITCH SEWING MACHINE Original Fi led March 23, 1952 6Sheets-Sheet l I I I nitor n e Wz'inem Jan. 5, 1937. TOPHAM I 2,066,373

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LOCKSTITCH SEWING MACHINE Original Filed March 23, 1932 6 Sheets-Sheet 6ZZZ-glass FLJQYJZ Patented Jan. 5, 1937 UNITED STATES PATENT OFFICELOCKSTITCH SEWING MACHINE Original application March 23, 1932, SerialNo.

600,654. Divided and this 1934, Serial No. 729,617.

application June 8, Renewed March 10,

15 Claims. (01. 112-57) The present invention relates to shoe sewingmachines which employ a hook needle to draw loops of needle threadthrough the work, and is herein illustrated as embodied in a machine ofthe McKay type such as that disclosed in the patent to Ashworth No.1,914,936 granted June 20, 1933.

The object of the invention is to improve the operation of shoe sewingmachines, and more particularly to provide improved devices for insuringproper formation and setting of each stitch at a uniform distance withinthe work during sewing and, when employed in a lockstitch machine, forcausing the final stitch to remain 15 above the surface of the workwhere the threads may be severed simultaneously.

In the machine herein illustrated the stitch is drawn down and set bythe needle thread takeup and a feature of the invention is embodied in20 a construction utilizing a thread lock for gripping the threadbetween the take-up and the thread supply, as the takeup completes itsthread drawing stroke, and after a supply of thread has been drawnthrough the tension for 25 the next stitch.

In lockstitch shoe sewing machines of ordinary construction, it has beenfound desirable to permit the last formed needle loop at the end of theseam to remain above the surface of the work as the machine is stopped,where the needle loop, together with the locking thread, may readily besevered by a single cutting stroke. In order to insure that a definiteamount of thread will remain above the surface of the work, according toanother feature of the present invention, a second thread lock isarranged between the takeup and the work for gripping the thread and.positively preventing the take-up from setting the final stitch.

Other features of the invention includes the devices, combinations andarrangements of parts hereinafter described and claimed, certain ofwhich, while adapted for use in sole sewing machines of the McKay type,are also capable of use with other types of sewing machines.

The several features of the present invention and the advantagesobtained thereby will be readily understood by those skilled in the artfrom the following description taken in connection with the accompanyingdrawings which illustrate an embodiment of the invention.

In the drawings, Fig. 1 is a View in side elevation of the completemachine; Fig. 2 is a view in front elevation, partly in section, showingthe take-up mechanism and thread clamps for the needle thread of themachine shown in Fig. 1; Fig. 3 is a view in side elevation of thetake-up mechanism and thread clamps shown in Fig. 2, a part of thecasing and the wax pot being shown in section; Fig. 4 is a sectionalplan View on an enlarged scale, of the thread locks and a portion of themechanism for operating them in positions assumed on stopping themachine; Fig; 5 is a detail view of a part of the mechanism shown inFig. 4, looking from the left; Fig. 6 is a detail view of a part of themechanism shown in Fig. 4 looking from the right; Figs. 7 and 8 arefragmentary views of portions of the thread lock operating mechanismstaken along the line 'l'l of Fig. 4, and illustrating successive stagesof operation; Fig. 9 is a sectional view taken on the line 99 of Fig. 1,looking from the front of the machine; Fig. 10 is a diagrammatic viewshowing the relative relations of the take-up and the thread locksduring the sewing operation while the needle loop is passing over theshuttle; Fig. 11 is a similar view showing the parts as the stitch isbeing set; and Fig. 12 is a view showing the same parts just before themachine stops with thread of the final stitch not drawn into the work.

The lockstitch shoe sewing machine herein illustrated is similar to thatdisclosed in the application of the present inventor, Serial No.600,654, filed March 23, 1932 of which the present application is adivision. A great many of the parts common to the two machines areillustrated in the accompanying drawings, but inasmuch as they are fullyillustrated and described in the above application, they will be onlybriefly referred to in the following description.

The illustrated machine is driven from an electric motor I2 through aclutch mechanism indicated in Fig. 1 in dotted lines. This clutchmechanism is controlled from a foot treadle M which is normally held inraised position by means of a spring IS. The clutch mechanism acts toconnect and disconnect the motor with a shaft l8 and a sleeve 20 in thebase of the machine, from which motion is transmitted to a verticalshaft 22 extending up to the sewing head of the machine. Rotation of theshaft 22 imparts a corresponding movement to a sewing shaft 24 foroperating the needle, shuttle and other related parts.

The shoe to be operated upon is supported on an angular horn 26 havingan inclined upper portion enclosing needle threading devices. Motion isimparted to the needle threading devices through a hollow vertical shaft28 connected through suitable gears to a horizontal shaft 30 and thevertical shaft 22 driven from the motor I2.

, The sewing head of the machine is provided with a straight hook needle32, a presser foot 34, a loop taker in the form of a, shuttle 36, tocarry the needle loop over the bobbin or locking thread, a feed point38, a take-up 40, a needle looper 42 and 'a thread finger 44, the latterof which is mounted in the horn. The upper end of the horn isconstructed with the usual needle opening to permit the needle to enterthe horn in receiving the thread from the looper.

The horn 26 is mounted on the machine to rotate a complete turn of 360degrees, and is provided with a downwardly extending hollow spindlehaving bearings between the upper and lower ends of the spindle and theframe of the machine. The shaft 28 is journalled within the spindle ofthe horn to rotate about an axis concentric with the axis of rotation ofthe horn, which coincides with the longitudinal axis of the needle.

A feature of the present invention relates to a thread lock for grippingthe thread to set the stitch uniformly through the action of the takeup40. The thread lock and take-up are illustrated in Figures 2 and 3 inwhich the thread lock, hereinafter referred to as the sewing threadlock, is indicated at 46. The needle thread 41 passes from a source ofsupply 48, and. through a tension device 50 of ordinary constructionprovided with an adjustable tension nut 52 for varying the amount oftension, thence around a shaft 54 carrying the thread lock 46 looselyjournalled in a bracket 56 attached to the machine, downwardly through awax pct 58 of ordinary construction, upwardly over a pulley 60 carriedby the bracket 56, downwardly around a pulley 62 at the end of thetake-up lever 40 through a pulley 64 on the bracket 56, and upwardlyinto the horn. In order to prevent entanglement of the thread about theend of the take-up lever, the pivot about which the pulley 62 at the endof the take-up rotates is provided with an elongated spindle 66 (seeFig. 3) extending from the axis of the pulley at right angles to theline of movement of the take-up. The take-up 40 is operated from a cam68 carried by the horizontal shaft 30 which forms a part of theoperating connections to the needle threading devices in the horn. Thetake-up is fulcrumed on a shaft I0 provided with a headed portion andsecured on a bracket 12 attached to the machine frame. Thread drawingand surrendering movements are imparted to the take-up throughconnections between the take-up and a cam slot 14 formed in the cam 68,which connections include a bell-crank "I5 formed with a sleeve portion18 fulcrumed on a shaft 00 secured to the frame of the machine, and alink 82 connected between the take-up lever and one end of the bellcrank. The other end of the bell-crank carries a cam roll 84 engagingthe cam slot 14. One end of the link 82 is directly pivoted to thetake-up lever 40, and the other end is loosely pivoted on a stud 86clamped within an adjusting slot in the bell-crank. The sleeve I8 of thebell-crank is loosely mounted on the shaft 80, and is prevented fromdisplacement by a collar 88 clamped at the end of the shaft.

The thread lock 46 is actuated to grip the thread between the take-upand the supply during each thread drawing stroke of the take-up as itreaches the lower portion of its stroke. The thread tension 50 offerssufficient resistance to cause the take-umin moving from the positionindicated in Figs. 2 and 10, to draw loop of needle thread from theshuttle toward the work. As the needle loop approaches the work, itengages the locking thread, indicated at 90, and draws it against thework. Thereafter, the resistance offered by contact of the thread withthe work exceeds the resistance offered by the thread tension, so that asupply of thread is drawn through the tension before the take-up reachesthe end of its thread drawing stroke. Just before the end of the take-upstroke is reached, the thread lock 46 is applied, and further movementof the take-up draws the needle loop a uniform distance into the workagainst the thread lock 46, as shown in Fig. 11. Thus, the threeoperations of drawing the needle loop against the work, measuring threadfrom the supply, and setting the stitch, are accomplished during asingle stroke of the take-up.

The thread lock 46 is actuated to grip the thread just before the needlethread take-up 40 reaches the end of its thread drawing stroke by acup-shaped-cam 92,. shown in Figs. 2 and 4 adjustably secured in arecess in the cam 60 by a set screw 94', and connections actuated by thecam comprising a lever 96 having a cam roll 98 at one end arranged toengage the cam 92, the shaft 54 which supports the thread lock 46, aspring I00 surrounding the shaft and a block I02 secured to the shaft 54by a set screw I04 (see Fig. 4). The thread lock 46 is formed as awasher movable toward and from a shoulder I06 formed on a sleeve I08surrounding the shaft 54 and loosely fitting within an opening in thebracket 56. The shaft 54 is mounted in the bracket 56 to both oscillateand move freely 'in a longitudinal direction. The lever 96 is clamped bymeans of a bolt IIO to the shaft 54 to oscillate the shaft when the camroll 98 is engaged by the cam 92. The block I02 is provided with a pairof projections II2 to cooperate with similarly shaped recesses II4contained in a block II6 mounted on the bracket 56 and is resilientlypressed by the spring I00 compressed between the block I02 on the shaft54 and a washer II8 thrusting against the bracket 56 to cause the threadlock 46 to grip the thread against the shoulder I06. As the shaft 54 isoscillated by the cam 92, the projections I I2 rise part way out of therecesses II4, moving the shaft 54 longitudinally to release the threadat the proper time to allow the take-up to measure thread during itsthread drawing stroke. The cam 92 is so proportioned that the time inwhich the cam roll is released to move under the action of the springI00 and the projections 2 enter the recesses II4 occurs just before thetake-up has completed its stroke. In order to adjust the timing, theblock II6 (see Fig. 5) is adjustably secured to the bracket 56 by a boltI 20 slidably arranged in a slot I22 in the bracket.

1 In accordance with another feature of the invention, in order tosimplify the act of severing the thread at the end of a seam, the loopof needle thread of the final stitch is positively prevented from beingdrawn into the work and is held in a position shown in Fig. 12, throughthe action of a second thread lock in the form of a washer I24,hereinafter referred to as the final stitch thread lock. This secondthread lock comprises the washer mounted loosely on a shaft I26 to bemoved, in gripping the thread, toward and from a shouldered sleeve I28surrounding the shaft. The sleeve I 28 is loose on the shaft I26 andslides freely in a longitudinal direction in an opening in the bracket56 but is held against angular rotation by a pin I30 projecting from thebracket 56, and passing through a slotted projection at one side of thesleeve I28.

In order to operate the second thread lock I24 efiectively to grip thethread, it must act during the thread drawing stroke of the take-up 40,and for this purpose the shaft I26 is operated by a cam I32 secured tothe end of the shaft 30. The shaft I26 carries an arm I34 fixed to itsinner end which is provided with a cam roll I36 in position to be actedupon by the cam I32. The shaft I26 is loosely mounted in the bracket 56,and is moved longitudinally by the action of a spring I38 surroundingthe central part of the shaft. The spring is compressed between a blockI40 clamped by a set screw I44 to the shaft and a washer I46 thrustingagainst the bracket 56. The block I40 is provided with a pair ofprojections I48 cooperating with similarly shaped recesses I50 in ablock I52 secured to the bracket 56, to impart a longitudinal movementagainst the action of the spring I38 as the shaft is oscillated by thecam I32. This longitudinal movement causes the thread lock I24 to movetoward and from the sleeve I28 to grip the thread in timed relation withthe operation of the take-up. The thread lock thus operates to grip thethread between the take-up and the work as the thread is being drawntoward the work by the take-up, preventing the take-up from drawing thelast formed needle thread loop and the locking thread against the work.To adjust the timing of the second thread lock, the block I52 isadjustably secured to the bracket 56 (see Fig. 6) by a bolt I54 passingthrough a slot in the bracket.

In order to prevent the thread lock I24 from acting to grip the needlethread during each stitch-forming cycle of the machine, the sleeve I28is provided with a pair of diametrically opposite recesses I56 tocooperate with projections I58 formed on a collar I60. The collar I60 isloosely mounted on the sleeve I28, and is provided with gear teeth I62(see Fig. 2) meshing with a segmental gear I64 extending from the hub ofa lever I66 loosely mounted on the sleeve I08. During normal operationof the machine, the collar I60 assumes a position diiferent from thatshown in Fig. 4, and in which the projections I58 coincide with therecesses I56 on the shouldered sleeve I28, so that the space between thethread lock washer I24 and the shoulder of the sleeve is greater thanthe thickness of the thread. As a result, the thread is free of the lockat all times during the sewing of a seam. As the machine is brought torest, the projections I58 are moved out of the recesses I56 to thepositions shown in Fig. 4, and the thread is gripped by the thread lock,permitting the needle loop to remain above the surface 01' the work, asin Fig. 12.

It is necessary during the time in which the final stitch thread lockI24 acts, to prevent the application of the sewing thread lock 46, asotherwise the thread would be broken by the take-up. For this purpose,connections operated during the completion of the final stitch as themachine is brought to rest, operate to release the sewing thread lock 46from engagement with the shoulder I06, and permit the application of thefinal stitch thread lock I24, and finally to release the thread lock I24from the sleeve I28, simultaneously with the release of the needlethread tension, so that the work may be withdrawn a short distance fromthe machine before severing the thread. These connections for actuatingthe thread locks in their proper sequence during the completion of thefinal stitch are operated by a stop mechanism which is of substantiallythe same construction as that described in Patent No. 1,874,690 grantedAugust 30, 1932 to Ashworth.

The stop mechanism which is rendered operative when it is desired tobring the machine to rest acts to disconnect the needle from itsactuating mechanism and lock it out of operation at the top of theretracting stroke and to raise the presser foot from engagement with thework as well as to actuate the thread locks and tension device in themanner just indicated. When the foot treadle I4 is released, ahorizontal shaft I68 in the sewing head (see Figs. 1 and 9), is rotatedin a clockwise direction. The shaft I68 is journalled in the machineframe and carries at one end an arm I10 loosely mounted thereon. Securedto the said end of the shaft is an arm I12 connected to the treadle I4by a link I14. This arm. is provided with a projection I16 extendingbeneath a rearward extension of the arm I10 and engaging said rearwardextension upon the release of the treadle. The arm I10 is connected to ashaft I18 by a link I80 con nected to the arm I10 at one end and at theother end to an arm I82 fixed to the shaft I18. Release of the foottreadle also acts to Swing an arm I84 attached at the rearward end ofthe shaft I18 in a counter-clockwise direction as viewed in Fig. 9. Thearm I84 extends downwardly, and loosely supports a pin I85 at its lowerend. The pin I85 is connected to the ends of a pair of links I86 and I81which, in turn, are connected to a lifting member I88 and a retainingmember I89, respectively, loosely suspended at their upper ends from thesewing shaft 24. The member I89 is provided with an eccentric strap I90surrounding an eccentric member I9I on the sewing shaft 24, but the hookmember I88 is supported loosely on the shaft itself, so that no movementis imparted to it by rotation of the shaft. When the shaft I 18 isrocked by releasing the foot treadle at the end of a seam, the liftingmember I89 is moved toward the right by the arm I84 against one arm of aT-shaped lug I92 projecting laterally from, an arm of a lever I93loosely mounted on a shaft I94 mounted in the machine frame. The shaftI94, being rotatably mounted, is provided at its rearward end with anarm I95 secured to the shaft and arranged with a portion I96 overlyingthe lug I92. This movement, of course, occurs only after the motor hasbeen disconnected from the machine, the sewing shaft continuing torotate under the momentum of the rotating parts. As the shaft continuesto turn, the hook I89 is forced beneath the lug I92 by a spring I91surrounding the link I81. When the lever I93 is actuated, an outwardlyextending arm thereon is moved downwardly to operate the thread locks 46and I24 through a second lever I98 (see Fig. 1) and a link I99connecting the two levers. The lever I98 is fulcrumed on abolt 200threaded into the frame of the machine, and is formed with openings Iand 202 for engagement with enlargements 203 and 204, respectively (seeFig, 4) formed at the ends of the levers 96 and I66, in the orderstated, for operating the thread locks. The lever I98 is maintained in aposition in which the sewing thread lock acts to grip the thread by aspring 205 connected to the machine frame, and the lever carries a pairof set screws 206 and 207 entering within the opening 2IlI to adjust therelative movement between the lever I98 and the sewing thread lock lever96.

As the stop mechanism begins its operation, lever I93 (see Fig. 9) inthe head of the machine begins its movement and the sewing thread lockoperating lever 96 is rocked with the shaft 54 to release the sewingthread lock 46. This movement also moves the lever I66, rotating theprojections I58 out of the recesses I56, so that as the take-up drawsthe final needle loop towards the work, the thread lock I24 will beoperated to grip the thread, and the thread lock 46 will be held inreleased position. The position of the lever 99 under thesecircumstances is shown in Fig. '7, in which the adjusting screw 29'! isshown as rocking the lever 96 to a position in which the sewing threadlock 46 is released.

In order to release the final stitch thread lock I24 as the main sewingshaft 24 continues to rotate, the lever 93 is rocked into the positionshown in Fig. 8, and a lug 298 formed on the lever 96 engages a finger209 on the arm I34, causing the arm I34 to be operated away from aposition in which the final stitch thread lock I24 grips the thread. Atthe same time that the thread locks are released, the tension on thethread is also released by a downwardly extending arm of the lever I98(see Fig. 1) and a rod ZID pivotally connected to the arm of the lever.The forward end of the rod carries a perforated enlargement 2I2 whichbears against the tension 59, and guides the thread between the tensionand the supply. At the end of the stop mechanism operation, the lever I98 is moved and the rod 2 II) releases the thread from the tension, sothat the work may be withdrawn from the machine without resistance.

The parts thus operated are retained in position by the action of theretaining member I89 engaging the lug I92 and the spring I91 whichsurrounds the link I81 acting to prevent release of the retaining memberI89 when the sewing shaft is brought to rest and until the treadle I4 isagain depressed.

As the machine is started by movement of thetreadle I4, the shaft I68 isrocked in a reverse direction, and the retaining member I89 is releasedfrom the lug I92 against the actionof the spring 597, by an arm 2I4carrying a roll fixed to the shaft IE8 and engaging a cam surface on theretaining member I89. The lifting member I88 is also retracted fromengagement with the lug I92 by movement of the arm I82 on the shaft H6as the treadle is depressed.

The nature and scope of the invention having been indicated, and anembodiment of the invention having been specifically described, what isclaimed is: a

1. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a thread tension, a looper, a take-upacting to draw down a loop of needle thread against the tension untilthe resistance offered by contact of the loop with the work exceeds theamount of tension and thereafter to draw the thread through the tensionfrom the supply for the next stitch, and a thread lock for gripping thethread between the take-up and the supply while the take-up completesits stroke to set the stitch.

2. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a thread tension, a looper, a take-upacting to draw down a loop of needle thread against the "tension untilthe resistance offered by contact of the loop with the work exceeds theamount of tension and thereafter to draw the thread through the tensionfrom the supply for the next stitch, and a thread lock arranged betweenthe take-up and the thread tension for gripping the thread between thetake-up and the supply while the take-up completes its thread drawingstroke and for retaining its grip on the thread as the take-up yields upthread to the other stitchforming devices.

3. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a looper, a loop taker and a take-up,mechanism for stopping the operation of the machine with the needledisengaged from, the work, and a thread lock arranged between the takeupand the work to grip the thread and prevent the take-up from drawing thelast formed loop of needle thread together with the locking threadagainst the work.

4. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a looper, a loop taker and a take-up,mechanism for stopping the operation of the machine with the needledisengaged from the work, a thread lock arranged between the takeup andthe work, and normally inactive mechanism rendered active in stoppingthe machine for actuating the thread'lock to grip the thread and preventthe take-up from drawing the last formed loop of needle thread togetherwith the locking thread against the'work. I

5. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a looper, a loop taker, a take-up, asewing shaft and suitable connections for actuating the stitch-formingdevices, means for driving the sewing shaft, means for disconnecting thesewing shaft from its driving'means and for rendering inoperative theactuating connections between the needle and shaft while the needle isat the limit of a loop drawing stroke, a thread lock arranged betweenthe take-up and the work and normally inactive mechanism rendered activein stopping the machine for actuating the thread lock to grip the threadand prevent the take-up from drawing the last formed loop of needlethread together with the locking thread against the work.

6. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a looper, a loop taker and a take-up,mechanism for stopping the operation of the machine with the needledisengaged from the work, a thread lock arranged between the takeup andthe work, normally inactive mechanism rendered active in stopping themachine for actuating the thread lock to grip the thread and prevent thetake-up from drawing the last formed loop of needle thread together withthe locking thread against the work and thereafter to release the threadfrom the grip of the thread lock.

7. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a looper, a loop taker and a take-up,mechanism for stopping the operation of the machine with the needledisengaged from the work, a thread lock arranged between the takeup andthe work, a cam for actuating the thread lock to grip the thread andprevent the take-up from drawing a loop of needle thread together withthe locking thread against the work as the take-up completes its threaddrawing stroke, and

normally inactive mechanism for preventing the T5 thread lock fromgripping the thread during sewing of a seam, said mechanism beingrendered active during stopping of the machine for permitting the threadlock to grip the thread under the action of the cam and thereafter forreleasing the thread from the grip of said thread lock.

8. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a looper, a loop taker, a take-up and athread lock arranged between the take-up and the supply of thread actingintermittently during sewing to grip the thread as each stitch is set, asecond thread lock arranged between the take up and the work to grip thethread and prevent the take-up from drawing the last formed loop ofneedle thread together with the locking thread against the work, andmeans for releasing the thread from the thread lock on the supply sideof the take-up as the second thread lock is actuated to grip the threadon the work side of the take-up.

9. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a looper, a loop taker, a take-up, athread lock arranged between the take-up and the supply of thread, asewing shaft and suitable connections for actuating the stitch-formingdevices comprising a cam shaft for actuating the thread lockintermittently during sewing to grip the thread as each stitch is set, asecond thread lock actuated by the cam shaft to grip the thread betweenthe take-up and the work and prevent the take-up from drawing a loop ofneedle thread together with the locking thread against the work, andnormally inactive mechanism for preventing the second thread lock fromgripping the thread during sewing of a seam, said mechanism beingrendered active during stopping of the machine for permitting the secondthread lock to grip the thread under the action of the cam shaft andthereafter for releasing the thread from the grip of said thread lock.

10. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a looper, a loop taker, a take-up, athread lock arranged between the take-up and the supply of thread, asewing shaft and suitable connections for actuating the stitch-formingdevices comprising a cam shaft for actuating the thread lockintermittently during sewing to grip the thread as each stitch is set, asecond thread lock actuated by the cam shaft to grip the thread betweenthe take-up and the work and prevent the take-up from drawing a loop ofneedle thread together with the locking thread against the work,normally inactive mechanism for preventing the second thread lock fromgripping the thread during sewing of a seam, said mechanism beingrendered active during stopping of the machine for permiting the threadlock to grip the thread under the action of the cam shaft, and means forreleasing the thread from the thread lock on the supply side of thetake-up as the second thread lock is actuated to grip the thread on thework side of the take-up.

11. A sewing machine having, in combination, stitch-forming devicesincluding a hook needle and a pivoted take-up lever for surrenderingthread as the needle is retracted from the work and for pulling thethread through the work after the thread is released from the needle, apulley on the take-up, and an elongated spindle extending from thecenter of the pulley perpendicular to the line of movement of thetake-up for preventing entanglement of the thread about the free end ofthe take-up.

12. A sewing machine having, in combination, stitch-forming devicesincluding a hook needle and a pivoted take-up lever for surrenderingthread as the needle is retracted from the work and for pulling thethread through the work after the thread is released from the needle, apulley on the take-up, and an elongated spindle extending at rightangles to the line of movement from the take-up for preventingentanglement of the thread about the free end of the take-up.

13. A lockstitch shoe sewing machine having, in combination, stitchforming devices including a hook needle, a take-up for yielding up andwithdrawing thread from the other stitch forming devices, a threadsupply, a thread lock acting between the take-up and the supply to gripthe thread as each stitch is being set, and means for actuating thetake-up while the thread is released from the lock to cause a length ofthread sufficient for the succeeding stitch to be drawn from the supply,and thereafter to set the stitch while the length of thread for thesucceeding stitch remains between the thread lock and the work.

14. A lockstitch shoe sewing machine having,

in combination, stitch forming devices including a hook needle, atake-up for drawing the needle loop down to the work and for setting thestitch at the end of its loop drawing stroke, a thread lock againstwhich the stitches are set, and means for actuating the take-up andthread lock to draw thread through the lock between the time when theneedle loop is drawn down and the time the stitch is set.

15. A lockstitch sewing machine having, in combination, stitch-formingdevices including a hook needle, a thread tension, a looper, a take-upacting to draw down a loop of needle thread against the tension untilthe resistance offered by contact of the loop with the work exceeds theamount of tension and thereafter to draw the thread through the tensionfrom the supply for the next stitch, a thread lock for gripping thethread between the take-up and the supply while the take-up completesits stroke to set the stitch, and normally inactive mechanism renderedactive in stopping the machine for preventing actuation of the threadlock during formation of the last stitch.

LAURENCE E. TOPHAM.

